Exercise's Effects on the Heart

Heart Attack and Sudden Death from Strenuous Exercise

A small percentage of heart attacks occur after heavy exertion.

High-Risk Individuals. In general, the following people should avoid intense exercise or embark on it only with carefully monitoring:

• Strenuous physical exertion is never recommended for people who have uncontrolled diabetes, uncontrolled seizures, uncontrolled high blood pressure, a heart attack within six months, heart failure, unstable angina, significant aortic valve disease, or aortic aneurysm.
• Older people should be cautious. Studies report that older people who first embark on vigorous exercise are at slightly higher than average risk for a heart attack during the first year, but over time, regular exercise is likely to reduce this risk.
• Experts generally recommend that moderate or severe hypertension (any systolic blood pressure over 160 mm Hg or diastolic pressure over 100 mm Hg) should be controlled to lower levels before starting a vigorous exercise program.
• Sedentary people should be cautious. One major study found that sedentary people who throw themselves into a grueling workout significantly increase their risk of heart attack.
• Episodes of exercise-related sudden death in young people are rare but of great concern. Some are preceded by syncope (fainting) , which is due to a sudden and severe drop in blood pressure. It should be noted that syncope is relatively common in athletes and is dangerous only in people with existing heart conditions. Young people with genetic or inborn heart disorders should avoid intensive competitive sports.
• Anabolic steroids or products containing ephedra have been associated with cases of stroke, heart attack, and even death.

The risk for heart attack from exercise should be kept in perspective, however. Some form of exercise carefully tailored to their specific conditions has benefits for most of these individuals. And in many cases, particularly when the only risk factors are being sedentary and older, exercise can often be increased over time until it is intense.

Hazardous Activities for High-Risk Individuals. The following activities may pose particular dangers for high-risk individuals:

• Intense workouts (snow shoveling, slow jogging, speed walking, tennis, heavy lifting, heavy gardening) may be particularly hazardous for people with risk factors for heart disease, particularly older people. They tend to stress the heart, raise blood pressure for a brief period, and may cause spasm in the arteries leading to the heart. (See image: Coronary Artery Spasm)
• Some studies suggest that competitive sports, which couple intense activity with aggressive emotions, are more likely to trigger a heart attack than other forms of exercise.

Listening for Warning Signs. It should be noted that according to one study, at least 40% of young men who die suddenly during a workout have previously experienced, and ignored, warning signs of heart disease. In addition to avoiding risky activities, the best preventive tactic is simply to listen to the body and seek medical help at the first sign of symptoms during or following exercise. They include the following:

• Irregular heartbeat
• Undue shortness of breath
• Chest pain